I don't know. If I'm running an application server with only my own code on a dedicated server, and I can flip some switches to make it go faster, then that's pretty nice, no? Might save me from upgrading to a bigger (pricier) server. What am I missing?

I mean, sure, that site is nuts, it sorely needs documentation. But not every scenario needs Spectre protection.

The problem with the scenario you describe is: how will you ensure that no one ever forgets that this server is vulnerable and can never be used for certain things? And everyone on here advocating turning off the mitigations is assuming the only exploits are the ones we know about. But when has that ever been the case. If more people turn off the mitigations black hats will be invested in finding ways to exploit it we haven't realised before.